Marijuana (Cannabis sativa) and derivatives have been used for medicinal and recreational purposes. The major active constituent extracted from Cannabis sativa is the classical cannabinoid Δ9-Tetrahydrocannabinol (Δ9-THC). The effects of such cannabinoids are due to an interaction with specific high-affinity receptors. Presently, two cannabinoid receptors have been characterized: CB1, a central receptor found in the mammalian brain and a number of other sites in peripheral tissues; and CB2, a peripheral receptor found principally in cells related to the immune system. The CB1 receptor is believed to mediate the psychoactive properties associated with classical cannabinoids. Characterization of these receptors has been made possible by the development of specific synthetic ligands such as the agonists WIN 55212-2 and CP 55,940.
In addition to acting at the cannabinoid receptors, cannabinoids such as Δ9-THC also affect cellular membranes, thereby producing undesirable side effects such as drowsiness, impairment of monoamine oxidase function and impairment of non-receptor mediated brain function. The addictive and psychotropic properties of some cannabinoids also limit their therapeutic value.
International Publication number WO 03/007887 A2 to Finke et al describes imidazole derivatives alleged to have binding affinity for the central cannabinoid receptor. International Publication number WO 03/027076 A2 to Kruse et al also describes some imidazole derivatives alleged to have binding affinity for cannabinoid receptors.